Conventionally, as disclosed in, for example, Japanese Laid-Open Patent Publication No. 11-68161, Japanese Laid-Open Patent Publication No. 2002-8409, Japanese Laid-Open Patent Publication No. 2007-27316, and Japanese Laid-Open Patent Publication No. 2007-96287, etc., there is an illuminating device for which a plurality of LED modules being light emitting modules for each of which a plurality of light emitting diodes (LEDs) are connected in series can be connected as light sources in parallel to a power supply. In such an illuminating device, in order to light the LEDs of each light emitting module almost uniformly, the power supply is provided as a constant-current power supply to supply a constant current to the light emitting module.
However, in the above-described illuminating device, since the power supply is provided as a constant-current power supply, this is effective when the connecting number of LED modules is preset, while in such a case where the connecting number of LED modules is arbitrarily increased or decreased, there is a problem that drive cannot be controlled in response to a state of the connected LED modules, such that current to be supplied to each LED module is insufficient or excessive, and the LEDs cannot be lit in a desired state.
The present invention has been made in view of such a problem, and an object thereof is to provide an illuminating device whose drive can be controlled in response to a state of the connected light emitting modules.